Angiotensin I-Converting Enzyme Inhibitory Activity of Two Peptides Derived from In Vitro Digestion Products of Pork Sausage with Partial Substitution of NaCl by KCl

This study aimed to identify angiotensin I-convertingenzyme (ACE)from in vitro digestion products of pork sausagewith partial substitution of NaCl by KCl (PSRK). Peptides from in vitro digestion products of PSRK were identified throughliquid chromatography with tandem mass spectrometry analysis coupledwith de novo sequencing. Subsequently, the ACE inhibitory peptidesLIVGFPAYGH and IVGFPAYGH were screened based on PeptideRanker, in silico absorption, molecular docking, and the determinationof ACE inhibitory activity. In addition, the ACE inhibitory peptidesLIVGFPAYGH and IVGFPAYGH were mixed-type inhibitors; these peptides'ACE inhibitory activities were expressed as the 50% inhibitory concentration(IC50) values in vitro, which were 196.16and 150.88 & mu;M, respectively. After 2 h of incubation, LIVGFPAYGHand IVGFPAYGH could be transported through Caco-2 cell monolayerswith paracellular passive diffusion. Furthermore, LIVGFPAYGH and IVGFPAYGHsignificantly increased the levels of ACE2 and nitric oxide whiledecreasing the levels of ACE, angiotensin II, and endothelin-1 inAng I-treated human umbilical vein endothelial cells, indicating theACE inhibitory effect of LIVGFPAYGH and IVGFPAYGH. In summary, LIVGFPAYGHand IVGFPAYGH from PSRK can be used as functional foods with antihypertensiveactivity.

Automated summary

This study identified ACE from the in vitro digestion products of pork sausage with partial substitution of NaCl by KCl. The ACE inhibitory peptides LIVGFPAYGH and IVGFPAYGH were screened, and their inhibitory activities were determined. It was found that LIVGFPAYGH and IVGFPAYGH can be transported through Caco-2 cell monolayers and have an ACE inhibitory effect. These peptides also increased the levels of ACE2 and nitric oxide while decreasing the levels of ACE, angiotensin II, and endothelin-1, suggesting their potential as functional foods with antihypertensive activity.